David Ash threw four touchdown passes and ran for another as No. 15 Texas shook off a slow start to roll over New Mexico State 56-7 Saturday night.

Ash threw two interceptions in the second quarter and the Longhorns' new up-tempo offense stalled as the Aggies took a 7-0 lead. Ash then connected on touchdown passes of 54 and 66 yards to John Harris and Daje (duh-jay) Johnson in the final two minutes of the first half.

In the third quarter, Ash turned a scramble into a 55-yard touchdown and passed to Malcolm Brown for a 74-yard score. After falling behind, Texas (1-0) scored 35 points on 15 snaps and finished with a school-record 715 total yards with Ash accounting for 434.

Andrew McDonald was 32-of-46 passing with one touchdown, but also had two turnovers for the Aggies (0-1), who went 1-11 last season.

Texas came into the season touting its new offense and the new confidence displayed in training camp by Ash, who spent the last two seasons under constant threat of being pulled for Case McCoy. Even coach Mack Brown had said his team is ready to challenge for the Big 12 title and return among the nation's elite.

But despite the new enthusiasm and bravado that comes with 19 returning starters, almost nothing went right early. Ash looked like the same quarterback of the last two years: talented but prone to mistakes.

The Longhorns had three first-half turnovers, two by Ash, and frustrated fans let loose with a few boos when McDonald connected with Joshua Brown for an 11-yard touchdown pass that gave New Mexico State a surprise lead late in the second quarter. The Aggies' touchdown came after Ash threw his second interception.

The shocking score line seemed to wake up the Longhorns and a flurry of big plays and touchdowns silenced the boos.The 715 total yards broke the Texas record of 692 set in 1998 when Heisman Trophy winner Ricky Williams was dashing through defense.

Ash, who last year might have collapsed after the early turnover or been pulled from the game, found Harris open on the sideline for Texas' first touchdown with 1:48 left in the half. After Texas used three quick timeouts to force New Mexico State to punt, Ash connected with Johnson across the middle and the receiver sped away from five defenders for another long score.

With momentum swung to Texas, New Mexico State gambled with an onside kick to open the second half. The Longhorns recovered and Johnson scored again four plays later, scooting around the left side on a sweep for a 21-7 Texas lead that broke the game open.

The Longhorns were just getting started and New Mexico State couldn't match Texas' speed in the open field. Ash's dash through the secondary and his long scoring pass to Brown turned it into a rout long before Ash connected with Mike Davis for his fourth touchdown pass — this one a short 25-yarder — in the fourth quarter.